W1型铁路弹条疲劳性能研究

Experimental study on the fatigue failure of W1-yype spring clip

对WJ-7型铁路弹条扣件系统中的W1型弹条在不同载荷幅值(7.5kN,10kN,12.5kN)下的疲劳性能进行实验研究,通过可靠性研究方法得到了包含存活率的P-F-N曲线(其中P为可靠度,F为弹条扣压力,N为循环次数),提出了不同可靠度的疲劳寿命方程。结果表明弹条扣压力随载荷循环次数衰减,扣压力衰减曲线呈三阶段变化,第二阶段占疲劳寿命的70%.且基本成线性。最后通过线性疲劳积累损伤理论建立了疲劳寿命预测模型,提出了采用微损实验来预测疲劳寿命的方法。

The fatigue performance of Wl-type spring clip for WJ-7-type railway spring fastener system under different load amplitudes(7.5kN,lOkN,12.5kN)is studied experimentally.The P-NF curves related to survival rates are obtained based on the reliability research methods・The fitting fatigue-life equation is given by calculating actual engineering reliability under different bolt pretightening force corresponding elastic fatigue-life.The results indicate that the clamping force of fastener decreases with increasing the load cycles・The pressure attenuation curve can be divided into three stages,and the second stage accounts for nearly 70%of the fatigue-life changing linearly.Finally,a model for fatigue-life prediction is proposed according to the linear fatigue accumulation damage theory,and a method based on the micro-damage experiment is provided to predict the fatiguelife.